1. Field of the Invention
The invention relates to a bearing arrangement and a coupling element of a spreading roll, comprising a spreading roll and a bent shaft which is surrounded by several successive roll segments that are mounted in bearings on the shaft and that are coupled and supported endwise on each other with flexible coupling elements. The successive roll segments that are interconnected with the flexible coupling elements constitute a unit that rotates around the bent shaft. The curved spreading roll is used for spreading different kinds of materials.
2. Description of the Related Art
Successive roll segments are conventionally mounted with dual bearings, i.e. two separate bearings, around a fixed shaft. Such a construction is disclosed for example in German Patents DE-2 108 702 and DE-2 131 590. British Patents GB-2 034 002 and GB-1 340 292 disclose rolls that have been mounted with double rolling bearings and that comprise, between the roll segments, a two-part supporting bearing which simultaneously acts as a turning joint. Finnish Patent Application FI-932 060 discloses a spreading roll where bearings are positioned at the ends of the roll segments in such a way that the bearings rest on the ends of the flexible coupling elements. EP-298 534 discloses a curved roll that is mounted with dual bearings and that comprises rolling bearings positioned at a distance from the coupling elements.
The roll segments are conventionally mounted with two rolling bearings around a fixed shaft. Such a support arrangement is naturally rather rigid with respect to rotation, which has resulted in such known coupling elements in old structures where the metal halves of the coupling situated around the rubber part are entirely unconnected. In other words, the rubber part is situated between metal sleeves or the like, whereupon the metal halves of the coupling start sometimes rotating eccentrically at high speeds. This slight eccentricity produces shaking that leads to a small difference in the direction, i.e. in a slight tilt, which causes the bearings to wear mechanically and the grease of the bearings to separate, so that the oil content of the grease flows out and the remaining mere binder or the like cannot lubricate the mechanism.